For future work, one can broaden our research by extending the RIS structure, i.e., the uniform-planar-array (UPA) [1]}, and designing the aerial-RIS trajectory to adapt to moving UAV-BSs under the mobility scenario [2]}. It is also essential to study other factors that affect the energy-efficiency, such as the battery consumption of the aerial platforms [3]}, [4]} and the power dissipation in the RIS hardware [5]}, [6]}. Moreover, the work on the methodology of RIS installation on the aerial platform can be performed [7]}, which is still in its infancy. Comparative research of our proposed aerial-RIS setup algorithm and other relaying methods, including amplify-and-forward (AF) [5]} and decode-and-forward (DF) architectures [9]}, [6]}, [5]} can be taken into account. Furthermore, to confront the higher-data-rate fronthaul links for the future wireless network [12]}, [13]}, [14]}, the application of signals with a higher spectrum can be contemplated for our proposed aerial-RIS backhaul system [15]}, followed by the measurement of its performance and reliability.
